High Tech Pet Rechargeable Power Pet Door BatteryEven during a power outage your dog can still have full access to his Power Pet door. This rechargeable battery operates your Power Pet door for approximately 1000 cycles should your power go out then automatically recharges through the pet door circuitry or with optional charger kit (model CRG-12) sold separately. Operates the Power Pet door without the need of an AC wall connection when used with the optional charger kit (sold separately). Our High Tech Pet Rechargeable Power Pet Door Battery is easy to install. Just snap it into the battery compartment and your Power Pet door will remain functioning in the case of a power outage.